Return-Path: X-Original-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 3180210358 for ; Mon, 24 Feb 2014 14:47:31 +0000 (UTC) Received: (qmail 57460 invoked by uid 500); 24 Feb 2014 14:47:25 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 57156 invoked by uid 500); 24 Feb 2014 14:47:23 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 56996 invoked by uid 99); 24 Feb 2014 14:47:20 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 24 Feb 2014 14:47:20 +0000 Date: Mon, 24 Feb 2014 14:47:20 +0000 (UTC) From: "Suresh Srinivas (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Created] (HDFS-6005) Simplify Datanode rollback and downgrade MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 Suresh Srinivas created HDFS-6005: ------------------------------------- Summary: Simplify Datanode rollback and downgrade Key: HDFS-6005 URL: https://issues.apache.org/jira/browse/HDFS-6005 Project: Hadoop HDFS Issue Type: Sub-task Components: datanode, namenode Reporter: Suresh Srinivas Assignee: Suresh Srinivas Problem: When rolling upgrade fails, the cluster can either be downgraded or rolled back. With the current functionality in this feature branch, it is possible to downgrade namenode, while datanode is incorrectly rolled back. This does not affect the cluster state. The old blocks that appear back on the datanode due to rollback will be deleted. Similarly it is also possible to rollback namenode, while datanode is not rolled back. This can cause problem where old blocks do not appear back on the datanode and can result in missing blocks. Solution: I propose making the following changes: During rollback or downgrade, the entire cluster must be restarted. The datanodes always restore the deleted blocks on restart and go back to trash disabled mode. There is no need for datanodes to be started up -rollingUpgrade -rollback, anymore. # On namenode downgrade, the restored blocks are deleted. # On namenode rollback, the restored blocks will be retained and any newly created blocks (since the start of rolling upgrade) are deleted. This is much simpler operationally and solves the problem described above. -- This message was sent by Atlassian JIRA (v6.1.5#6160)